This invention relates generally to printed circuit boards (PCB""s). In particular, the present invention is a mechanism for inserting and extracting printed circuit boards into and out of a peripheral component interconnect (PCI) computer system housing. The mechanism provides a mechanical advantage to supply the necessary forces to engage and disengage male and female connector pairs of a pair of PCB""s mounted within the PCI computer system housing.
One type of computer system housing employs a PCB input/output (I/O) connection system known as the peripheral component interconnect (PCI) system. The popularity of the PCI system has grown to a point where it is the preferred I/O connection system for larger server computers as well as workstation computers. The PCI system allows one or more microprocessors (i.e., PCB""s) to be interconnected with attached external devices.
The PCI system includes a computer system housing defined by a plurality of walls. At least one of these walls is removable to provide access to an interior region of the housing to allow PCB""s to be inserted into and removed from the housing. The PCB""s are releasably connectable to a central processing unit of the computer system through a PCB known as a xe2x80x9cmother boardxe2x80x9d, or a xe2x80x9cbackplane boardxe2x80x9d, as it is vertically mounted as a back wall of the computer system housing. PCB""s, typically known as xe2x80x9cdaughter boardsxe2x80x9d are electrically connected (i.e., plugged) via mating pairs of electrical connectors mounted to the daughter boards and the mother board. These electrical connectors typically include a plurality of socket terminals (i.e., female connector) that are attached to the daughter boards which are plug compatible with pin terminals (i.e., male connector) attached to the mother board to allow data and/or power to be transmitted between the joined components.
With this type of computer system, it is considered standard procedure to either correct faulty components or to incorporate changes (i.e., upgrades) in an existing system by removing the faulty PCB""s (i.e., daughter boards), or the PCB""s requiring upgrades, and substituting new PCB""s in their place. To replace faulty or obsolete PCB""s with new PCB""s requires that the faulty/obsolete PCB""s be extracted from the mother board (i.e., vertical PCB) by un-mating of the electrical connectors coupling these components. By the same token, inserting new PCB""s into the computer system requires mating of the electrical connectors of the PCB""s and mother board.
Although the coupling of the pin terminals (i.e., male component) with the socket terminals forms a reliable electrical connection, there are some drawbacks in the use of male/female PCB electrical interconnects. For example, because of the necessity to create a reliable electrical connection between these mating male and female components of the electrical connector, these PCB electrical connectors often require large mechanical forces in order to engage and disengage these male and female connector components. Due to these high magnitude engagement/disengagement forces during the PCB extraction/insertion process and the confined working environment of computer systems, damage to the PCB""s (both mother and daughter boards), the male and female connector components and/or electrical components on the PCB""s is of great concern. For example, these large engagement/disengagement forces can cause flexing of the PCB""s during the extraction/insertion process that could cause bent pin terminals on the mating electrical connectors or damage to devices located on the PCB in the vicinity of the mating connectors. Pin damage renders the electrical connector useless, and repair of the electrical connector (if possible) is time consuming and costly. As such, otherwise operational PCB""s having connectors with damaged pin terminals are often discarded simply because of the damaged pins. Moreover, damaged electrical connectors can result in a loss of electrical contact between mated male/female electrical components that can cause start-up problems, intermittent operation or total inoperability, thereby causing the overall quality of the computer system to be diminished.
To prevent damage, technicians often employ a pair of lever mechanisms that provide a mechanical advantage to supply the necessary mechanical forces to extract and insert PCB""s. Although, these lever mechanisms provide the necessary mechanical forces to extract and insert PCB""s, these forces are typically applied at the rear of the PCB to be removed/inserted and far removed from the mating electrical connector components. As such, the lever mechanisms can also cause PCB flex that could cause damage to PCB components or the electrical connectors. Moreover, this pair of lever mechanisms can apply these mechanical extraction/insertion forces to the PCB in an uneven manner potentially further damage to the electrical connectors and PCB components.
There is a need for a mechanism for extracting and inserting PCB""s from and to a PCB mother board. In particular, there is a need for an extraction/insertion mechanism that provides a mechanical advantage by supplying the mechanical forces necessary to disengage (i.e., un-mate) and engage (i.e., mate) male and female electrical connectors mounted to the PCB""s. The extraction/insertion mechanism should direct these mechanical forces at the mating female/male electrical connector components to provide the mechanical advantage where it is needed most. In addition, the extraction/insertion mechanism should substantially prevent PCB flex in the vicinity of the mating female/male electrical connector components, so as to prevent PCB damage, electrical connector damage (i.e., pin terminal damage) and/or damage to electrical components mounted to the PCB during the extraction/insertion process (i.e., mating/un-mating process). This damage could otherwise render the electrical connectors, the PCB and electronic components useless, or diminish the overall quality of the computer system. Moreover, the extraction/insertion mechanism should reliably provide these features so as to preclude time consuming and costly repairs of the electrical connectors and the PCB""s and electronic components mounted to the PCB""s. Furthermore, the extraction/insertion mechanism should be readily removable from and installable to the PCB""s. Lastly, the extraction/insertion mechanism should be relatively easy and inexpensive to manufacture.
The present invention is a mechanism for use in insertion and extraction of a first printed circuit board (PCB) to and from a second PCB so as to engage and disengage an electrical connector of the first PCB to and from a corresponding electrical connector of the second PCB. The insertion and extraction mechanism includes a first member affixed to the first PCB immediately adjacent to the electrical connector. The first member stiffens the first PCB in the vicinity of the electrical connector. A second member is affixed to the second PCB immediately adjacent to the corresponding electrical connector. A movable fastener is engageable with the first and second members. Movement of the fastener in a first direction causes the first PCB to be inserted to the second PCB which causes the electrical connector to be engaged with the corresponding electrical connector. Movement of the fastener in a second direction causes the first PCB to be extracted from the second PCB which causes the electrical connector to be disengaged from the corresponding electrical connector.
In one aspect of the present invention, the first member is a T-shaped stiffener bar that includes a stiffening portion and an engagement portion, the second member is a mounting block and the fastener is a threaded fastener. The stiffening portion is immediately adjacent to and extends along the electrical connector. The threaded fastener is carried by the engagement portion and engages a threaded opening in the mounting block to insert and extract the first PCB to and from the second PCB thereby engaging and disengaging the electrical connector to and from the corresponding electrical connector. In another aspect of the present invention, the insertion and extraction mechanism includes an alignment pin that is mounted to and extends outwardly from the engagement portion of the stiffener bar. The alignment pin engages an alignment opening in the mounting block to insure that the electrical connector and the corresponding electrical connector are properly aligned with one another upon engagement and disengagement during insertion and extraction of the first PCB to and from the second PCB. In a further aspect of the present invention, the electrical connector is a male connector and the corresponding electrical connector is a corresponding female connector.
In this insertion and extraction mechanism of the present invention, the threaded fastener provides a mechanical advantage by supplying the mechanical forces necessary to disengage (i.e., un-mate) and engage (i.e., mate) the male and female electrical connectors mounted to the first and second PCB""s. The insertion and extraction mechanism directs these mechanical forces at the mating female/male electrical connector components to provide the mechanical advantage where it is needed most. In addition, the stiffening portion of the stiffener bar of the insertion and extraction mechanism substantially prevents flex of the first PCB in the vicinity of the mating/un-mating female/male electrical connector components, so as to prevent PCB damage, electrical connector damage (i.e., pin terminal damage) and/or damage to electrical components mounted to the PCB during the extraction/insertion process (i.e., mating/un-mating process). This damage could otherwise render the electrical connectors, the PCB and electronic components useless, or diminish the overall quality of the computer system. Moreover, the insertion and extraction mechanism reliably provides these features so as to preclude time consuming and costly repairs of the electrical connectors and the PCB""s and electronic components mounted to the PCB""s. Furthermore, the stiffener bar and mounting block of the insertion and extraction mechanism are readily removable from and installable to the PCB""s. Lastly, the components of the extraction/insertion mechanism are relatively easy and inexpensive to manufacture.